The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 2011
Filed:
Oct. 03, 2008
Lars Andersson, Kirchdorf, CH;
Hubert Braendle, Oberengstringen, CH;
Klaus Bohnert, Oberrohrdorf, CH;
Lars Andersson, Kirchdorf, CH;
Hubert Braendle, Oberengstringen, CH;
Klaus Bohnert, Oberrohrdorf, CH;
ABB Research Ltd., , CH;
Abstract
To measure a sum of electrical currents in different conductors, light is led in an optical sensing fiber around all the conductors. The sensing fiber can be wound around the conductors in a single loop or in several individual loops. Interspersed polarization maintaining fibers and retarders can be used to transfer the light between individual loops for preventing undesired signals from stray magnetic fields. The method has high accuracy is particularly suited for measuring large currents that sum up to zero.